Apparatus for rolling sections from metal powder



June 1, 1965 K. CLAUS ETAL, 3,186,030

APPARATUS FOR ROLLING SECTIONS FROM METAL POWDER Filed March 22, 1962 3 Sheets-Sheet 1 June 1, 1965 K. CLAUS ETAL 3,186,030

' APPARATUS FOR ROLLING SECTIONS FROM METAL POWDER Filed March 22, 1962 3 Sheets-Sheet 2 June 1, 1965 K. cLAuS ETAL 3,136,030

I APPARATUS FOR ROLLING SECTIONS FROM METAL POWDER Filed March 22, 1962 United States Patent 3,186,030 APPARATUS FOR ROLLING SECTIGNS FROM METAL POWDER Kurt Claus, Lintorf, near Dusseldorf, and Felix Pollmeier,

Dusseldorf, Germany, assignors to Schloemaun Aktiengesellschaft, Dusseldorf, Germany Filed Mar. 22, 1962, Ser. No. 181,764 Claims priority, application Germany, Apr. 1, 1961, Sch 29,490 2 Ciaims. ((3113-12) It is known to convert metal powder by rolling into bands and wires by introducing metal powder into the roll gap of a vertically disposed dual rolling mill.

In order to enable a metal powder which has been heated above the recrystallisation temperature to be compressed by rolling into a solid length of homogeneous structure, a compression ratio of 1:3 to 1:4 is required. This compression must take place within the gripping angle of the rolls. Since the gripping angle is constant for a determined powder and a determined type of surface of the rolls, the compression ratio obtained is dictated solely by the diameter of the rolls. If the necessary compression is reached before the narrowest roll gap, a rolling action will occur which produces a stretching and/ or widening of the band or wire being rolled. The rolling action can be avoided in the case of bands and wires by selecting suitable roll diameters. If it nevertheless occurs, stretching or widening in these cases is scarcely disadvantageous.

The rolling of powder to form a section having diifering thickness in the direction of the rolling pressure leads to difficulties on account of the differing compression ratio of the metal powder in the roll gap. Hitherto it was not possible for example to roll an I-section from powder, because the necessary compression of the thin web between the rolls was attained far sooner than the corresponding compression of the flanges. For example the compression of the web may occur even before the narrowest roll gap, while the necessary compression of the thicker flanges is not yet completed and takes place either later, for example in the narrowest roll gap, or not at all. In every case the abovementioned rolling effect would occur in the web, which naturally leads to longitudinal tensions between Web and flanges.

The invention aims at permitting the rolling of metal powder into a section having differing thickness in the direction of the rolling pressure.

According to the invention it is proposed to elfect the compression of the powder by a plurality of serially disposed pairs of rolls, the first pair of rolls effecting the compression of the narrowest portion of the section, for example of the web, to the final dimensions and also efiecting a slight compression of the wider portions of the section, for example of the flanges, while the succeeding pairs of rolls compress the broad portion (flanges) in stages until the final dimensions are reached. The compression of the broad parts (flanges) which is possible in the first set of rolls is at the same time utilised to give those portions cohesion. Another feature of the invention comprises the utilization, between the sets of rolls, of closed guides, which may be constructed as heating units for the purpose of keeping the half-finished section at the working temperature.

Embodiments of the invention are illustrated diagrammaticaly by way of example in the accompanying drawings, in which:

FIGURE 1 shows a set of rolls for rolling an I-section,

FIGURE 2 the appertaining plan view, i

FIGURE 3 a first set of rolls for rolling a triangular section,

3,186,036 Patented June 1, 1965 ice FIGURE 5 the second set of rolls for rolling the triangular section,

FIGURE 6 the plan view corresponding to FIGURE 5,

FIGURE 7 the third set of rolls for rolling the triangular section, and

FIGURE 8 the plan view corresponding to FIGURE 7.

In FIGURES 1 and 2, 1 designates a charging hopper which delivers metal powder 2 heated above the recrystallization temperature into a roll gap which is formed between two adjustable profile rolls 3, 3a. The rolls 3, 3a form a closed pass, being stepped in accordance with the section and having the radii R and r. The radii R of the rolls 3, 3a are so selected that in the region of the gripping angle the necessary compression ratio of 1:3 to 1:4 is achieved and thus the web 211 of the I-section is rolled to the final dimension. The roll peripheries which are formed by the radii r are intended for rolling the flanges 2b, 21:. Within the gripping angle, however, only a slight compression of the flanges 2b, 2c takes place, for which reason further compression is necessary. This compression is effected in the succeeding sets of rolls, in which the rolls, like those previously described, have the radii R, r and R, r respectively. a designates the gripping angle. Where its side intersects the pass, the rolls begin to drive the metal powder and to press it into the roll gap. 4 and 5 designate guides which completely enclose the half-finished section. These guides can in addition be constructed as heating units, whereby the section is kept at the working temperature.

The invention is not restricted solely to the embodiment illustrated and described, because it is also possible to roll the web 2a to the final dimensions in a plurality of passes.

In the embodiment illustrated by Way of example in FIGURES 3 to 8, three sets of rolls are similarly disposed one above the other, the first set being illustrated in FIG- URES 3 and 4, the second in FIGURES 5 and 6, and the third in FIGURES 7 and 8. or here again designates the gripping angle of the rolls. In the first set of rolls, illustrated in FIGURES 3 and 4, use is made of two rolls 10 and II the axes 12 and 13 of which enclose a determined angle, so that between the two rolls a triangular section of the shape 14 of metal powder can be produced. The roll 10 has two edges 15 and 16, which bear against the roll 11 by corresponding annular surfaces, so that the pass for the formation of the section 14 is enclosed annularly. On the two rolls 10 and 11 illustrated in FIG- URE 3 a feeding hopper is provided, corresponding to the hopper I in FIGURES 1 and 2. For the sake of clarity of illustration the feeding hopper is here omitted.

In the next set of rolls, illustrated in FIGURES 5 and 6, the angle which is formed by the roll axes 12 and 13a is considerably smaller than the corresponding angle in the case of the set of rolls illustrated in FIGURES 3 and 4. The section 14, which has been formed in the set of rolls illustrated in FIGURES 3 and 4, here assumes the shape 17.

After leaving the set of rolls illustrated in FIGURES 5 and 6, the section 17 is fed to the set of rolls illustrated in FIGURES 7 and 8, in which it assumes the finished section IS. The axes 12 and 13b of the rolls here enclose a still smaller angle than in the case of those illustrated in FIGURES 5 and 6. As can be seen in FIGURES 7 and 8, the finished section 18 has a shape one side of which has the dimension b. On the opposite side the section ends almost in an acute angle and there has only the very small width a. This small width a was produced in the first set of rolls illustrated in FIGURES 3 and 4, while the opposite side of the section 14 in FIG- URES 3 and 4 has the dimensions 3.6611 in the region of FIGURE 4 the plan view corresponding to FIGURE 3. the gripping angle 00. On leaving the first set of rolls,

illustrated in FIGURES 3 and 4, this size is reduced to the size 2.66b. If the section which passes out of the first set of rolls, illustrated in FIGURES 3 and 4, is fed to the second set of rolls, illustrated in FIGURES 5 and 6, it leaves the last mentioned set of rolls with the width 2.66b, while the width of the opposite side a has remained unchanged. On leaving the second set of rolls, illustrated in FIGURES 5 and 6, the side a still remains unchanged while the opposite side now has only the size 1.8311. In the last set of rolls, illustrated in FIGURES 7 and 8, the shorter side a again remains unchanged, while the op posite side has now been reduced to the size b.

We claim:

1. An apparatus for forming an elongated structural shape from metal powder, said shape having a thin section and a thicker section transversely spaced from said thin section, said apparatus comprising a first pair of opposed rolls, means for feeding metal powder between said rolls, the distance between a portion of said rolls being equal to the finished thickness of said thin section, the distance between another portion of said rolls being greater than the finished thickness of said thicker section but small enough to provide for partial compaction of the powder in said thicker section, a second pair of opposed rolls, the distance between a portion of said second rolls being equal to the finished thickness of said thin section, the distance between another portion of said second rolls being less than the distance between said other portion of said first rolls but greater than the finished thickness of said thicker section to provide for further compaction of the powder only in said thicker section, and a third pair of opposed rolls, the distance between a portion of said third rolls being equal to the finished thickness of said thin section, the distance between another portion of said third rolls being equal to the finished thickness of said thicker portion, whereby said thin section is formed to finished thickness between said first rolls and said thicker section is progressively formed between said first, second and third rolls while maintaining the finished thickness of said thin section.

2. An apparatus as defined in claim 1, in which the axes of said first rolls are disposed at an angle with respect to each other, the axes of said second and third rolls being disposed at angles with respect to each other which are progressively less than the angle between the axes of said first rolls.

References Cited by the Examiner UNITED STATES PATENTS Re. 16,097 6/25 Grey --66 361,822 4/87 Hohre et a1. 189 845,329 2/07 Bottomley 25-21 1,826,813 10/31 Oberschulte 8066 2,039,204 4/36 Young 2521 2,620,513 12/52 Cryor et al 189 FOREIGN PATENTS 1,004,457 3/57 Germany.

WILLIAM J. STEPHENSON, Primary Examiner. 

1. AN APPARATUS FOR FORMING AN ELONGATED STRUCTURAL SHAPE FROM METAL POWDER, SAID SHAPE HAVING A THIN SECTION AND A THICKER SECTION TRANSVERSELY SPACED FROM SAID THIN SECTION, SAID APPARATUS COMPRISING A FIRST PAIR OF OPPOSED ROLLS, MEANS FOR FEEDING METAL POWDER BETWEEN SAID ROLLS, THE DISTANCE BETWEEN A PORTION OF SAID ROLLS BEING EQUAL TO THE FINISHED THICKNESS OF SAID THIN SECTION, THE DISTANCE BETWEEN ANOTHER PORTION OF SAID ROLLS BEING GREATER THAN THE FINISHED THICKNESS OF SAID THICKER SECTION BUT SMALL ENOUGH TO PROVIDE FOR PARTIAL COMPACTION OF THE POWDER IN SAID THICKER SECTION, A SECOND PAIR OF OPPOSED ROLLS, THE DISTANCE BETWEEN A PORTION OF SAID SECOND ROLLS BEING EQUAL TO THE FINISHED THICKNESS OF SAID THIN SECTION, THE DISTANCE BETWEEN ANOTHER PORTION OF SAID SECOND ROLLS BEING LESS THAN THE DISTANCE BETWEEN SAID OTHER PORTION OF SAID FIRST ROLLS BUT GREATER THAN THE FINISHED THICKNESS OF SAID THICKER SECTION TO PROVIDE FOR FURTHER COMPACTION OF THE POWDER ONLY IN SAID THICKER SECTION, AND A THIRD PAIR OF OPPOSED ROLLS, THE DISTANCE BETWEEN A PORTION OF SAID THIRD ROLLS BEING EQUAL TO THE FINISHED THICKNESS OF SAID THIN SECTION, THE DISTANCE BETWEEN ANOTHER PORTION OF SAID THIRD ROLLS BEING EQUAL TO THE FINISHED THICKNESS OF SAID THICKER PORTION, WHEREBY SAID THIN SECTION IS FORMED TO FINISHED THICKNESS BETWEEN SAID FIRST ROLLS AND SAID THICKER SECTION IS PROGRESSIVELY FORMED BETWEEN SAID FIRST, SECOND AND THIRD ROLLS WHILE MAINTAINING THE FINISHED THICKNESS OF SAID THIN SECTION. 